CSAMA/CA is widely known as a technique for avoiding collision of signals transmitted by wireless communication apparatus. CSAMA/CA is an abbreviation for “carrier sense multiple access/collision avoidance.”
Further, as widely known as a hidden terminal problem, even when the technique of CSAMA/CA is used, signals may collide with each other. In Patent Literature 1, while a subject terminal is transmitting a packet, collision of the packet with a packet transmitted by another terminal is monitored. When the packet collision has been detected, the subject terminal stops the packet transmission.